The present invention relates to an opening and closing device that automatically opens and closes an opening and closing cover by rotation of a motor, and also relates to an electronic apparatus and an image forming apparatus that are equipped with such an opening and closing device.
Some electronic apparatuses such as an image forming apparatus read data from a recording medium, such as a memory card and an optical disc, which is inserted into an insertion opening by a user, and perform an image formation process, such as photo printing, using the read data. When the recording medium is pulled out from the insertion opening while data is being read, the data in the recording medium may be damaged. In attempt to overcome such a problem, an opening and closing device that opens and closes an insertion opening with a cover is used.
For example, Japanese Patent Laid-Open Publication No. 2005-74981 discloses an opening and closing device that swingably supports a cover, by a swinging shaft of a cover body, between a closed state in which the cover covers a memory slot and an open state in which a memory can be attached to and detached from the memory slot. When the cover is in a position close to the closed state, an elastic force of a twisted coil spring acts on the cover in a closing direction, and when the cover is in a position close to the open state, the elastic force of the twisted coil spring acts on the cover in an opening direction. The load of an oil damper acts on the swing of the cover. This configuration is believed to improve operability and use experience, by providing assistance in the manual operations of the cover by the user through the elastic force of the twisted coil spring, and by controlling the swing speed to an appropriate speed, and thus preventing the cover from becoming partially open.
Furthermore, in order to eliminate the need for the user to operate the cover, there is an opening and closing device provided with a motor that rotates in both a forward direction and a backward direction and a transmission mechanism in which the forward rotation and the backward rotation of the motor are selectively transmitted to the cover.
However, when the rotation stop position of the motor is changed due to errors such as a mounting error, the load that acts on the motor and the transmission mechanism becomes excessively large. In addition, the load of the motor also becomes large in a case in which the motor is excessively rotated in order to securely close the cover. These may cause a possibility of generation of abnormal noise from the motor and breakage of the motor and the transmission mechanism. Moreover, in a case in which a finger of the user is caught while the cover is being closed, the operation of the cover cannot be stopped.
In view of the foregoing, an object of the present invention is to provide an opening and closing device that can automatically open and close a cover without making a load of a motor and a transmission mechanism excessively large, and to provide an electronic apparatus and an image forming apparatus that are equipped with such an opening and closing device.